Almost hate to ask this question but I've never really seen any discussion on it.

I've had other vehicles with larger displacement engines than my truck. For instance my Chevelle had a 454 which is much larger than the CTD. The 454 used five quarts of oil I seem to recall.

Why does the CTD or for that matter the Duramax and PS take so much oil. 3 gallons in the CTD just makes me wonder why.

 

Because......

 

Straight from de Horse's Mouth. On the CTD de dippy stick is longer. Seriously, the oil serves the function of lubricant as well as coolant. Your Turbocharger is cooled by oil. With the high turbo temperatures it takes lots of oil flowing through it to keep it cool without overheating the oil. Thats the reason for the longer dippy do stick.

 

Hmmmm my VW Passat TDI takes a little over 4 quarts of oil. And it is a turbo.......... ??? Don't know how long the dipstick is tho....

 

I've been thinking about this, and here's my $0.02. Diesels require a higher volume of oil flow - big internal "leaks" like piston spray nozzles and the turbo aren't found on a Chevy big-block. A Powerstroke uses the oil to run the injectors, there's another internal "leak". There has to be a bigger reserve to draw this larger volume from so as not to pump the sump dry. Also, typical diesel customers (us pickup drivers aren't them, think school busses and straight trucks) expect to have longer oil change intervals, you need more oil there to absorb the soot and other crap generated inside an engine. The added volume doesn't do much to keep things cool though, the water to oil heat exchanger that your oil filter hangs off of does that. Functions as an oil heater, too, when the oil is cooler than the water.

 

Ever notice how quick the oil on diesel engines get blacker sooner than gassers?<br>I think the main differance between gas engine oils &amp; diesel engines is it's ability to remove more redisuel contaminants left in the combustian process.<br>More oil = greater carbin removal<br><br>Sound good on paper 8)<br><br>db<br>

 

I think the '03 stays cleaner longer. Mine at 12k I was still able to see through it on the dipstick....

 

Hence the longer oil drain intervals --less soot to remove on cleaner burning diesels.<br><br>db

 

Yep makes sense..

 

Spots<br><br>I didn't think you could get the TDI in a passat--is it the same 1.9?

 

Yeah late '96 and '97. Early '96 and '95 were the old diesels. Aug '96 build date on mine. Same 1.9l as in the Jettas and Golfs. Still waiting for this fall for the Passat diesel to be in North America.....

 

Some turbochargers are watercooled rather than oil cooled, hence more water and less oil.

 

he he he he hence I get it

 

Actually, it's not a lot for a diesel with the displacement of ours. I believe our trucks are limited to amount of crankcase lubricant because of the design of the trucks suspension. As a comparison the Yanmar diesels on my sister's boat each hold 7 gallons (similar displacement). The oil pan's sump runs the length of the block.